Colimaite
Chemical formula: K<sub>3</sub>V<sup>5+</sup>S<sup>2-</sup><sub>4</sub>
Colimaite is a newly discovered, extremely rare vanadium and potassium sulfide, forming microscopic, hexagonal crystals in volcanic fumaroles.
Properties
- Luster
- Metallic
- Streak
- Black
- Transparency
- Opaque
- Crystal system
- Hexagonal
Diagnostic features
## Identification Identification of colimaite is impossible without advanced laboratory techniques, such as scanning electron microscopy (SEM) with EDS analysis or X-ray diffraction (XRD). In collecting conditions, identification relies solely on trust in the label and the reputation of the supplier, confirming its origin from the type locality. ## Distinguishing from Similar Minerals Due to its unique chemical composition and occurrence, it is unlikely to be confused with other minerals in its natural environment. Other black, microscopic minerals from volcanic fumaroles require chemical analysis for differentiation. ## Crystal Forms Colimaite forms hexagonal, tabular or prismatic crystals with a hexagonal outline. They occur as single, isolated crystals or small, loose clusters on the substrate.
Geological environment
## Genesis Colimaite is a mineral of volcanic origin. It forms through the sublimation process from volcanic gases rich in sulfur, vanadium, and potassium. It crystallizes at high temperatures (approximately 450-600°C) in active fumaroles, depositing on the surface of volcanic ash. ## Mineral Associations This mineral co-occurs with other volcanic sublimation products, such as shcherbinaite (V₂O₅), bannermanite, thenardite (Na₂SO₄), and halite (NaCl). ## Localities The only confirmed locality for colimaite in the world is its type locality – an active fumarole on the summit of Colima volcano, located on the border of the states of Colima and Jalisco in Mexico.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of a colimaite specimen is determined by the abundance and size of the microscopic crystals on the rock matrix. The most desirable samples are those with clearly visible (under a microscope) clusters of well-formed, hexagonal crystals. Due to its extreme rarity, any authentic specimen is valuable. ## Popular Localities The only source of specimens is Colima volcano in Mexico. The material is collected under extremely difficult and dangerous conditions, making it almost inaccessible on the commercial market. Specimens primarily come from scientific expeditions.
Care and storage
## Cleaning Colimaite specimens are extremely delicate and sensitive to moisture. They should not be cleaned by any mechanical or chemical methods. Any attempts at cleaning may destroy the microscopic crystals. ## What to Avoid Contact with water, water vapor, and chemicals must be strictly avoided, as the mineral is water-soluble. It should be protected from changes in temperature, humidity, and vibrations. ## Storage Specimens should be stored in tightly sealed, dry containers (e.g., "perky box" type) under stable room conditions, away from sources of moisture and direct sunlight. Due to their microscopic size, specimens are usually mounted on special pedestals and require careful handling.